Cumulative effects of 20-year exclusion of livestock grazing on above- and belowground biomass of typical steppe communities in arid areas of the Loess Plateau, China

Overgrazing affects typical steppe community in ways similar to grasslands in other areas. Exclusion of livestock grazing is one of the main management practices used to protect grasslands. However, it is not known if longterm exclusion of livestock grazing has positive effect on above- and belowground community properties in typical steppe of the Loess Plateau. We studied the long-term (20-year) cumulative effects of exclusion of livestock grazing on above- and belowground community properties compared with that before exclusion of livestock grazing in a typical steppe of the Loess Plateau, NW China. Our results show that twenty-year exclusion of livestock grazing significantly increased above- and belowground biomass, species richness, cover and height for five different com munities. Most of belowground biomass was in the 0–20 cm horizon and grazing exclusion increased biomass especially at the depth of 0–10 cm. Our study suggests that long-term exclusion of livestock grazing can greatly improve community properties of typical steppe in the Loess Plateau.